Process vessel with integral evaporator

ABSTRACT

A process vessel containing both an evaporation zone for evaporating a liquid feed and a treatment zone for treating the resulting vapor comprises an injector having an orifice, the orifice being in the evaporation zone, at least one evaporation surface for evaporating feed and generating vapor, the evaporation surface being located in the evaporation zone, wherein the injector orifice and the evaporation surface are positioned to prevent the formation of a drop at the orifice, a treatment zone for treating the vapor and at least one heater associated with at least a portion of the process vessel.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Division of copending application Ser. No.10/095,879 filed Mar. 12, 2002, the contents of which are herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to one or more process vessels eachprocess vessel containing both a treatment zone and an evaporation zone;the evaporation zone for vaporizing a liquid feed within the processvessel. The present invention also relates to a single, sequential, orparallel process of vaporizing a liquid feed within the processvessel(s).

BACKGROUND OF THE INVENTION

Before a catalyst is selected for use in a commercial application, forexample hydrocarbon reactions in petroleum refining, a great number ofcatalysts may be examined for use in the envisioned application. A largenumber of newly synthesized catalytic compositions may be considered ascandidates. It then becomes important to evaluate each of the potentialcatalysts to determine the formulations that are the most successful incatalyzing the reaction of interest under a given set of reactionconditions.

Two key characteristics of a catalyst that are determinative of itssuccess are the activity of that catalyst and the selectivity of thecatalyst. The term activity refers to the rate of conversion ofreactants by a given amount of catalyst under specified conditions, andthe term selectivity refers to the degree to which a given catalystfavors one reaction compared with another possible reaction, see,McGraw-Hill Concise Encyclopedia of Science and Technology, Parker, S.B., Ed. in Chief; McGraw-Hill: New York, 1984; p. 8.

The traditional approach to evaluating the activity and selectivity ofnew catalysts is a sequential one. When using a micro-reactor or pilotplant, each catalyst is independently tested at a set of specifiedconditions. Upon completion of the test at each of the set of specifiedconditions, the current catalyst is removed from the micro-reactor orpilot plant and the next catalyst is loaded. The testing is repeated onthe freshly loaded catalyst. The process is repeated sequentially foreach of the catalyst formulations. Overall, the process of testing allnew catalyst formulations is a lengthy process at best.

Combinatorial chemistry deals mainly with the synthesis of newcompounds. For example, U.S. Pat. No. 5,612,002 B1 and U.S. Pat. No.5,766,556 B1 teach an apparatus and a method for simultaneous synthesisof multiple compounds. Akporiaye, D. E.; Dahl, I. M.; Karlsson, A.;Wendelbo, R. Angew Chem. Int. Ed. 1998, 37, 9-611 disclose acombinatorial approach to the hydrothermal synthesis of zeolites, seealso WO 98/36826.

Combinatorial methods present the possibility of substantiallyincreasing the efficiency of catalyst evaluation. Recently, efforts havebeen made to use combinatorial methods to increase the efficiency anddecrease the time necessary for thorough catalyst testing. For example,WO 97/32208-A1 teaches placing different catalysts in a multi-cellholder with the heat absorbed or liberated in each cell being measuredto determine the extent of each reaction. Thermal imaging has also beenused; see Holzwarth, A.; Schmodt, H.; Maier, W. F. Angew. Chem. Int.Ed., 1998, 37, -47, and Bein, T. Angew. Chem. Int. Ed., 1999, 3-3.Measuring the heat absorption or liberation and thermal imaging mayprovide semi-quantitative data regarding activity of the catalyst inquestion, but they provide no information about selectivity.

Some attempts to acquire information as to the reaction products inrapid-throughput catalyst testing are described in Senkan, S. M. Nature,July 1998, 4(23), 3-353, where laser-induced resonance-enhancedmultiphoton ionization is used to analyze a gas flow from each of thefixed catalyst sites. Similarly, Cong, P.; Doolen, R. D.; Fan, Q.;Giaquinta, D. M.; Guan, S.; McFarland, E. W.; Poojary, D. M.; Self, K.;Turner, H. W.; Weinberg, W. H. Angew Chem. Int. Ed. 1999, 4-8 teachusing a probe with concentric tubing for gas delivery/removal andsampling. Only the fixed bed of catalyst being tested is exposed to thereactant stream, with the excess reactants being removed via vacuum. Thesingle fixed bed of catalyst being tested is heated and the gas mixturedirectly above the catalyst is sampled and sent to a mass spectrometer.

Attempts have been made to apply combinatorial chemistry to evaluate theactivity of catalysts. Some applications have focused on determining therelative activity of catalysts in a library; see Klien, J.; Lehmann, C.W.; Schmidt, H.; Maier, W. F. Angew Chem. Int. Ed. 1998, 37, 39-3372;Taylor, S. J.; Morken, J. P. Science, April 1998, 0(10), 7-270; and WO99/34206-A1. Some applications have broadened the information sought toinclude the selectivity of catalysts. WO 99/19724-A1 discloses screeningfor activities and selectivities of catalyst libraries havingaddressable test sites by contacting potential catalysts at the testsites with reactant streams forming product plumes. The product plumesare screened by passing a radiation beam of an energy level to promotephotoions and photoelectrons which are detected by microelectrodecollection. WO 98/07026-A1 discloses miniaturized reactors where thereaction mixture is analyzed during the reaction time usingspectroscopic analysis.

In order to determine the activity and selectivity of multiplecatalysts, arrays of reactors have been designed to simultaneouslyexamine multiple catalysts using the above mentioned analysistechniques. For example, EP 1108467 A2 teaches reactors with removablesections to allow easy introduction of catalyst to the reactor bed. Thereactors are sealed using o-rings to allow quick connection of thereactor parts and also provide a reliable seal between the reactor partsand between each reactor and its environment.

Many reactors available currently are designed for the situation wherethe feed streams are all of the same phase, for example two feedcomponents that are both gases. Many process technologies andchemistries require higher-pressure gas-phase catalysis, in which aliquid feedstock is vaporized before contacting the catalyst. This maybecome challenging due to the fact that many seals used forcombinatorial arrays have a temperature limitation that is below thebubble point of many reactor inlet compositional mixtures. For example,the long-term temperature limitation on a typical O-ring seal is about170° C., while the bubble point of C₆ to C₉ hydrocarbons, for exampletoluene, at operating pressures of about 300 psig (2172 kPa) to about450 psig (3220 kPa) are between about 180° C. and about 240° C. at ahydrogen to toluene molar ratio between about 1 and about 3.

U.S. Pat. No. 5,453,526 B1 teaches a catalytic reactor where liquidmedia can be continuously introduced, evaporated, and fed to a catalyticreaction. U.S. Pat. No. 3,359,074 teaches a polycondensation system of asingle vertically extending column which is transversely partitioned todefine, in descending order, a reaction chamber, an evaporator chamber,and a finishing chamber. Two articles, Bej K. S.; Rao, M. S. Ind. Eng.Chem. Res., 1991 30 (8), 1819-1832, and Eliezer K. F.; Bhinde, M.;Houalla, M.; Broderick, D.; Gates, B. C.; Katzer, J. R.; Olson, J. H.Ind. Eng. Chem. Fundam., 1977, 16 (3), 380-385 show where additionalparticles are used to aid in flow distribution before a feed iscontacted with a catalyst. What is needed is an evaporator that can beintegrated into a process vessel, that accommodates a liquid feed sothat the seals will not be compromised during operation of the processvessel, while providing for the feed to be in a vapor phase duringreaction.

However, evaporators in general have some inherent problems associatedwith their operation. One problem associated with evaporators in generalis non-uniform mixing of a liquid feed and a gas feed. Non-uniformmixing may occur when both a gas and a liquid are introduced to anevaporator through a common inlet. The dual feed of liquid and gascauses alternating regions of gas entrainment and liquid pulsation beingintroduced to an evaporator, and therefore regions of low concentrationof the vaporized species followed by regions of high concentration ofthe vaporized species being sent to a reactor bed.

Another problem associated with non-uniform vaporization occurs mainlybecause of a non-uniform flow of liquid into an evaporator. In the caseof slower moving flow, a liquid issuing from an orifice into anevaporator can form droplets that detach at a regular periodicitybecause of the fluid dynamics of the liquid. The periodic formation anddetachment of droplets leads to non-uniform vaporization within theevaporator.

What is needed is an evaporator for use in a process vessel thatovercomes the problems of non-uniform mixing and non-uniformvaporization associated with evaporators in general.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to provide a process vessel forvaporizing a liquid feed and treating the resulting vapor in the processvessel. It is further an object of the present invention to provide aprocess of vaporizing a liquid feed and treating the vapor within theprocess vessel.

In accordance with the present invention, a process vessel is providedfor vaporizing a liquid feed within an evaporation zone beforeprocessing the feed in a treatment zone of the process vessel. Theprocess vessel includes an evaporation zone, an injector having anorifice for injecting the liquid feed into the evaporation zone, atleast one evaporation surface, a treatment zone, and a heater associatedwith a portion of the process vessel. The evaporation surface and theinjector orifice are positioned within the evaporation zone so that theevaporation surface interferes with the formation of a drop of liquidfeed at the orifice and a thin liquid film of the liquid feed is createdon the evaporation surface. The heater heats the liquid feed within theevaporation zone to a temperature sufficient to vaporize the liquidfeed. It is preferred that the evaporation surface be a bed of packing.

Further in accordance with the present invention, a process is providedfor vaporizing a liquid feed within the process vessel. The inventiveprocess includes the steps of providing at least one evaporation surfacein an evaporation zone of the process vessel, injecting a liquid feedinto the evaporation zone through an injector orifice, heating andvaporizing the liquid feed within the evaporation zone of the processvessel. A gap formed between the injector orifice and the evaporationsurface is sufficiently small so that the evaporation surface interfereswith the formation of a drop of liquid feed at the orifice. The liquidfeed is instead directed to form a thin liquid film on the evaporationsurface which facilitates uniform vaporization and uniform concentrationin the resulting vapor. The vaporized feed is flowed to a treatment zoneof the process vessel and treated within the treatment zone to generatean effluent. It is preferred that the evaporation surface be a bed ofpacking.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an exploded side view of a reactor.

FIG. 2 is a top view of a insert.

FIG. 3 is a cross-sectional side view of an assembled reactor.

FIG. 4 is a side close up view of the orifice of the injector and thepacking.

FIG. 5 is a side view of an alternative assembled reactor.

FIG. 6 is a side view of an assembled array.

FIG. 7 is a perspective view of the array and the quick connect system.

DETAILED DESCRIPTION OF THE INVENTION

For ease of understanding, the present invention will be explained belowin terms of the preferred embodiment where the process vessel is areactor having an evaporation zone and a reaction zone. It must beunderstood however, that other vessels are within the generally broadscope of the invention. Furthermore, other treatment zones in additionto a reaction zone are within the generally broad scope of theinvention. Referring to the figures, there is shown a novel and improvedreactor 10 for evaporating liquid feed to form a vapor and reacting saidfeed in the presence of catalyst to make a product. The inventivereactor 10 prevents seals 28 and 30 and from being compromised andmaintains a reliable seal between reactor 10 and the environment whilealso providing for a liquid feed to be vaporized within reactor 10 asrequired by a reaction. Reactor 10 is particularly useful for evaluationof a catalyst 24 for a particular reaction. The inventive reactor 10 mayalso be used in an array 120 for the simultaneous reaction of a liquidfeed in the presence of several catalysts and for the evaluation ofmultiple catalysts in a combinatorial method. The integratedvaporization of the liquid feed within the reactor makes reactor 10 moreversatile than previous reactors used for the combinatorial processbecause it allows for a liquid component to be introduced to reactor 10,even if it needs to be in the vapor phase before it is contacted withcatalyst 24, and reactor 10 can perform the vaporization without seals28 and 30 failing and experimental results being compromised.

A. Reactor

Turning to FIG. 1, reactor 10 includes a housing 12 for housing reactor10, a header 14 which provides inlets for the feed to housing 12, aninsert 16 attached to header 14 which retains an evaporation zone 18 forvaporizing the liquid feed, an evaporator heater 20 (see FIG. 3) forproviding the heat necessary to vaporize the liquid feed to form avapor, and a receptacle 22 which retains a catalyst 24, catalyst 24forming a reaction zone 26. The vapor is contacted with catalyst 24 andreacted to form a product. A gas feed may also be introduced to reactor10, mixed with the vapor in the evaporation zone 18, and reacted withthe vapor in the presence of catalyst 24 to form the product gas.

The liquid feed may be any liquid component or mixture of liquidcomponents, that is able to be vaporized under predeterminedtemperatures and pressures and is intended to undergo a reaction that iscapable of being catalyzed by catalyst 24. The feed is preferred to be aliquid hydrocarbon mixture. Examples of hydrocarbon intended for the usein reactor 10 are aromatic, aliphatic, and naphthene compounds havingsix or more carbon atoms, preferably six to nine carbon atoms. Examplesof intended feed components are benzene, toluene, xylenes, ethylbenzenes, cumene, higher alkyl substituted benzenes, cyclohexanes,cyclopentanes, higher alkyl substituted cyclic paraffins, pentanes,hexanes, heptanes, octanes, nonanes, decanes, and higher molecularweight aliphatics and mixtures of the above. Alternatively, the liquidfeedstock may be or may contain one or more components having hydrogen,carbon, and another element such as oxygen, chlorine, sulfur, nitrogen,and the like.

A gas feed is not necessary for the use of reactor 10, but is includedin the discussions below merely to exemplify reactions involving a gasfeed as well as a liquid feed. The gas feed may be any gas that canactivate or reactivate surface reactive sites or undergo reaction thatis capable of being catalyzed by catalyst 24 and could be an organic orinorganic gas. Examples of gas feeds are hydrogen gas, oxygen gas orlight hydrocarbons in the gas phase such as methane or ethane.Alternatively, the gas feed could be an inert gas, such as Nitrogen, toact as a carrier for the vaporized liquid feed but not intended to reactin reaction zone 26. The feed to the reactor of the present inventionmay be one or more gas phase feeds, one or more liquid phase feeds, or acombination of one or more gas phase feeds and one or more liquid phasefeeds.

Both the liquid feed and the gas feed are introduced to reactor 10 inmeasured amounts, and with known compositions so that the amount of eachcomponent being introduced to reactor 10 is known. The known amount ofeach component entering reactor 10 combined with the measured flow rateand the analyzed composition of the product gas is used to determine theactivity, feed conversion, major product and byproduct selectivities andyields of catalyst 24 in reactor 10.

A first seal 28 is placed between the header 14 and the housing 12 toprovide a barrier between reactor 10 and its environment and a secondseal 30 is placed between the insert 16 and receptacle 22 to preventleaks between the insert 16 and receptacle 22. The removable parts ofreactor 10, along with seals 28 and 30, allow for easy assembly anddisassembly of reactor 10, as well as allowing individual parts to bereplaced if needed. For example, if receptacle 22 becomes damaged, itcan be replaced easily with an identical receptacle 22 simply by placingthe new receptacle 22 into reactor 10 and engaging seals 28 and 30.Other parts that are not damaged, do not need to be replaced. Theability of housing 12, insert 16 and receptacle 22 to be removed andreplaced allows easy assembly of reactor 10, which is beneficial for theexperimental setup of a combinatorial array 120.

Dimensions will be provided for the elements of reactor 10, however theinventive reactor 10 of the present invention is not limited to thedimensions described below, which are provided simply for context in thepreferred case of a combinatorial-scale reactor to be used in an array.It is conceivable that reactor 10 could be scaled up to a pilot plant oreven a commercial scale or scaled down to micro-scale without varyingfrom the generally broad scope of the invention.

1. Housing

As is best shown in FIG. 1, housing 12 includes an inlet end 32 forreceiving feeds and an outlet end 34 for products. Housing 12 encasesevaporation zone 18 and reaction zone 26. Housing 12 includes a shoulder36 at inlet end 32 of housing 12, a main section 38 between shoulder 36and outlet end 34, and a product conduit 40 at the outlet end 34.Product conduit 40 is attached to housing 12 at the outlet end 34 andallows a path for product to be withdrawn from reactor 10. Shoulder 36includes a surface 42 for seal 28 to engage between housing 12 andheader 14. Seal 28 prevents feeds from leaking from reactor 10 into theenvironment. Seal 28 may be retained by shoulder 36 of housing 12 or itmay be retained by header 14 without varying from the scope of theinvention.

Seal 28 may be any type capable of forming a reliable, pressure-tightseal between housing 12 and header 14, but it is preferred that seal 28be of a type that allows quick assembly of reactor 10. An example of anacceptable seal 28 being an elastomeric O-ring, or set of O-ringsengaged between housing 12 and header 14. However, typical elastomericO-ring seals have a maximum temperature limitation for long-termoperation of between about 170° C. and 300° C., which is lower than thebubble points of most liquid feeds that will be introduced to reactor10. For example, boiling points of C₆ to C₉ hydrocarbons at pressures ofbetween about 400 psig (2860 kPa) and about 500 psig (3351 kPa) rangefrom about 300° C. and about 400° C. Note that the present invention isnot limited to operating pressures in the range of 400 psig (2860 kPa)to 500 psig (3351 kPa). Reactor 10 of the present invention could beoperated at ambient pressure or in vacuum, or at pressures higher than500 psig (3351 kPa). The only limitation on operating reactor pressureis a differential pressure limitation on seal 28.

Because of bubble or boiling points that are higher than maximum seallimitations, many liquid feeds cannot be vaporized upstream of reactor10, because their elevated temperatures would compromise the integrityof seals 28 and 30. To solve this problem, an evaporator 44 is placedwithin reactor 10, downstream of seal 28 so that the maximum temperaturelimitation is not reached at seal 28. It is also desirable to keep seals28 and 30 in a cool zone that is separate from the heated evaporationzone 18.

Housing 12 and shoulder 36 are preferably cylindrical in shape, but maybe of another geometric shape. For ease of discussion, housing 12 andshoulder 36 will each be described as a cylinder having a length and adiameter, but it must be emphasized that the invention is not limited toa cylindrical shape having the size described herein. Other shapes andsizes of housing 12 could also be successfully employed. For the purposeof combinatorial use, reactor 10 is preferred to be small and easy tomanipulate so that an array 120 of multiple reactors 10 can be assembledeasily without the use of bulky parts.

In one embodiment, main section 38 of housing 12 may have a length ofbetween about 13 cm and 14 cm and an inner diameter of between about 0.4cm and about 0.5 cm. Shoulder 36 may have a length of about 1.0 cm and adiameter of between about 0.8 cm and about 1.0 cm. Product conduit 40may have an inner diameter of less than 1 mm to about 1.5 mm. However,housing 12, shoulder 36 and product conduit 40 are not limited to theabove dimensions and could be scaled up or down without varying from thescope of the present invention.

Housing 12 is preferably constructed out of a material that is inert toreaction with the liquid and gas feeds, is resistant to corrosion, canwithstand temperatures of from about 10° C. to about 1000° C., and hasgood heat transfer properties. Examples of suitable materials ofconstruction include metals and their alloys, low grade steel, stainlesssteels, super-alloys like Incolloy, Inconel and Hastelloy, engineeringplastics and high temperature plastics, ceramics such as silicon carbideand silicon nitride, glass, and quartz. A preferred material ofconstruction of housing 12 is 321 stainless steel and a preferredmaterial of construction of shoulder 36 is 316 stainless steel.

2. Header

As shown in FIG. 1, header 14 and insert 16 are connected to each otherso that header 14 and insert 16 form a single piece. Header 14 andinsert 16 may be connected by any number of methods such as threading,bolting or welding, but it is preferred that they be able to bedisengaged from one another so that packing 76 may be changed out ifdesired.

Header 14 provides fluid to inlet end 32 of housing 12. Header 14 alsoprovides a surface 46 for seal 28 to engage between header 14 andhousing 12 at shoulder 36, however seal 28 could engage between housing12 and insert 16. Header 14 includes an injector 48 for a liquid feedinlet, a gas feed inlet 50, a diluent gas inlet 52 and a guide tube 56for a thermocouple 54 to measure the temperature within reactor 10.Header 16 is received by housing 12 at inlet end 32.

It is preferred that the cross-section of header 14 be of the samegeneral shape as the cross-section of housing 12 so that header 14 willeasily fit within shoulder 36 of housing 12 within predeterminedtolerances. It is preferred that header 14 be generally cylindrical, butheader 14 could be generally of another geometric shape. For ease ofdiscussion, header 14 will be described as being generally cylindricalwith a length and a diameter. Header 14 fits within shoulder 36 ofhousing 12, engaging with seal 28, so that a portion of header 14 isabove shoulder 36 of housing 12.

The length of header 14 is preferably larger than the length of shoulder36 of housing 12 and the diameter of header 14 is preferably slightlysmaller than the diameter of shoulder 36 of housing 12 within tolerancelimits so that an adequate seal can be formed between header 14 andhousing 12. The diameter of header 14 is also preferred to be largeenough so that there is enough area injector 48, gas feed inlet 50,diluent gas inlet 52 and guide tube 56. In one embodiment, header 14 mayhave a length between about 1.0 cm and about 1.5 cm and a diameter ofbetween about 0.8 cm and about 0.9 cm. However, header 14 is not limitedto the above dimensions and could be scaled up or down without varyingfrom the scope of the present invention.

Like housing 12, header 14 is preferably constructed out of a materialthat is inert to reaction with the liquid and gas feeds, is resistant tocorrosion, can withstand temperatures of from about 10° C. to about1000° C., and has good heat transfer properties. It is preferred thathousing 12 and header 14 be made from similar, or identical materials.Examples of suitable materials of construction include metals and theiralloys, low grade steel, stainless steels, super-alloys like Incolloy,Inconel and Hastelloy, engineering plastics and high temperatureplastics, ceramics such as silicon carbide and silicon nitride, glass,and quartz. A preferred material of construction of header 14 is 316stainless steel.

Injector 48 passes through inlet end 32 of housing 12 via header 14 andis in fluid communication with the interior of insert 16 so thatinjector 48 extends substantially into insert 16, and liquid feed isintroduced through an orifice 66 of injector 48 into insert 16.Preferably, orifice 66 is located within evaporation zone 18 so that theliquid feed is introduced directly into evaporation zone 18. Preferably,injector 48 is placed so that it is approximately centered radialywithin the insert 16. The radial centering allows for uniformdistribution of the liquid feed within evaporator 44. Injector 48 ispreferably tubular with a small inside diameter and an orifice 66. Inone embodiment the diameter of orifice 66 of injector 48 may be about0.2 mm. The length of injector 48 that is within insert 16 may be about5 cm.

Gas feed inlet 50 extends through header 14 and is in fluidcommunication with insert 16 so that a gas feed introduced to the insert16 enters upstream of a liquid feed introduced to insert 16. Diametersof gas feed inlet 50 may be larger than the diameter of liquid feedinlet. The diameter of gas feed conduit is chosen to accommodate apredetermined flow rate of gas feed. In one embodiment gas feed inlet 50may have a diameter of less than 1 mm. The length of gas feed inlet 50is approximately the same as the length of header 14.

Diluent gas inlet 52 extends through header 14 and through a fluid path68 in reactor 10 so that the diluent gas can bypass catalyst 24 anddilute the product stream and prevent condensation, as discussed below.The diluent gas may be any gas used to dilute the product and suppressthe partial pressure of the product or unreacted feed to preventcondensation. It is preferred that the diluent gas be the same gas asthe gas feed so that they may be introduced from a common reservoir, butany gas may be used to dilute the product stream. The diameter ofdiluent gas inlet 52 is chosen to accommodate a predetermined flow rateof the diluent gas. In one embodiment, diluent gas inlet 52 may have aninner diameter less than 1 mm. The length of diluent gas inlet 52 isapproximately the same as the length of header 14.

Optional thermocouple 54 is placed within reactor 10 for measuring thetemperature within housing 12. Preferably, optional thermocouple 54measures the temperature within reaction zone 26. In one embodiment,thermocouple 54 is retained by a guide tube 56 in header 14 and extendsalong the length of insert 16 and passes into receptacle 22 so that asensor 70 of thermocouple 54 is generally centered within reaction zone26. However, only the location of sensor 70 effects the invention.Thermocouple 54 may be placed so that it is inserted through the sidesof housing 12 and receptacle 22 so that sensor 70 is generally centeredwithin reaction zone 26.

Optional guide tube 56 provides a way for a thermocouple 54 to be easilyplaced into reactor 10 to measure the temperature within reaction zone26. The diameter of guide tube 56 depends on the diameter ofthermocouple 54. In one embodiment, the inner diameter of guide tube 56may less than 1 mm.

However, injector 48, gas feed inlet 50, diluent gas inlet 52 and guidetube 56 are not limited by the above dimensions and could be scaled upor down without varying from the scope of the present invention.

Guide tube 56 is preferably constructed out of a material that is inertto reaction with the liquid and gas feeds, is resistant to corrosion,can withstand temperatures of from about 10° C. to about 1000° C., andhas good heat transfer properties. It is preferred that guide tube 56 isconstructed from similar or identical materials as the housing 12 andheader 14. Examples of suitable materials of construction include metalsand their alloys, low grade steel, stainless steels, super-alloys likeIncollsy, Inconel and Hastelloy, engineering plastics and hightemperature plastics, ceramics such as silicon carbide and siliconnitride, glass, and quartz. A preferred material of construction ofguide tube 56 is 321 stainless steel.

3. Insert

Header 14 and insert 16 are disengageably connected so that header 14and insert 16 form a single piece. Header 14 is adjacent to insert 16 sothat injector 48 and gas feed inlet 50 are in fluid communication withevaporation zone 18. Header 14 and insert 16 may be connected by anynumber of methods such as threading or bolting, but it is preferred thatthey be able to be disengaged from one another so that packing 76 may bechanged out if desired.

Header 14 and insert 16 are placed within housing 12 so that seal 28 isengaged between header 14 and housing 12, sealing reactor 10 from itsenvironment and so that insert 16 is within receptacle 22. Insert 16 ispreferably removable. Insert 16 includes an inlet end 72 and an outletend 74. Insert 16 contains packing 76 to form a bed 78 withinevaporation zone 18 for vaporizing the liquid feed to form a vapor.Although particulate packing 76 as described is preferred, otherevaporation surfaces may be employed instead of a particulate packing 76(see below).

A fluid permeable member 80 is attached at outlet end 74 of insert 16 toretain packing 76, but still allow fluids, such as the gas feed and thevapor to pass into receptacle 22 to be contacted with catalyst 24. Fluidpermeable member 80 is preferably a sintered metal, such as Hastelloy,but could be any material that is permeable to the fluids flowing intoreaction zone 26 in receptacle 22 and sufficiently strong to supportpacking 76. Other possible materials of fluid permeable member 80include glass, sintered glass, Raney metals, electro-bonded membranes,etched alloy membranes, and fine meshed screens with gaps smaller thanthe minimum packing size, but large enough to allow the gas feed andvapor to flow adequately.

Packing 76 could be in any form, so long as it interferes with theformation of a droplet (described below) and provides surfaces 82 forthe liquid feed to form a thin liquid film 84. Packing 76 may beparticulate packing, as shown in FIG. 4, or it may be a prefabricated,structured monolithic packing, or it may be another means to interferewith droplet formation and provide surfaces for the formation of a thinliquid film 84, such as a metal insert placed within evaporation zone 18near orifice 66. For ease of discussion, packing 76 is described as aparticulate packing having a diameter.

Thin liquid film 84 allows efficient evaporation of the liquid feed whenheat is provided by an evaporator heater 20. Packing 76 is preferablyinert to the gas feed and the liquid feed and may be any inert packingmaterial, such as alumina, and preferably microporous alumina. Packing76 may be of a uniform size with the same diameter for each particle, orof a random size with minimum and maximum particle diameters. Theminimum diameter of packing 76 is preferably larger than the diameter oforifice 66 of injector 48 so that packing 76 does not clog injector 48,and the maximum diameter of packing 76 should be no larger than about10% of the inner diameter of insert 16 to prevent the formation of wallflow along interior surface of insert 16. In one embodiment, thediameter of packing 76 may be between about 0.21 mm and about 0.42 mm.

Insert 16 is preferably of the same general shape as housing 12 so thatit will fit easily within housing 12. Insert 16 is preferablycylindrical in shape, but may be of another geometric shape. For ease ofdiscussion, insert 16 is described as a cylinder having a length and adiameter. In one embodiment, insert 16 may have a length of about 10 cmand a diameter of about 0.3 cm. The diameter of insert 16 is chosen sothat insert 16 will fit within receptacle 22 within predeterminedtolerances. Insert 16 is not limited to the above dimensions and couldbe scaled up or down without varying from the scope of the presentinvention.

Insert 16 is preferably constructed out of a material that is inert toreaction with the liquid and gas feeds, is resistant to corrosion, canwithstand temperatures of from about 10° C. to about 1000° C., and hasgood heat transfer properties. It is preferred that insert 16 beconstructed of a similar, or identical material as the housing 12 andheader 14. Examples of suitable materials of construction include metalsand their alloys, low grade steel, stainless steels, super-alloys likeIncolloy, Inconel, Hastelloy, engineering plastics and high temperatureplastics, ceramics such as silicon carbide and silicon nitride, glass,and quartz. A preferred material of construction of insert 16 is 321stainless steel.

Insert 16 also provides a surface 86 for seal 30 to engage betweeninsert 16 and receptacle 22. Seal 30 prevents the feeds from leakingpast catalyst 24 and prevents the diluent gas from passing intoreceptacle 22 and coming into contact with catalyst 24. Seal 30 may beretained by insert 16, header 14 or receptacle 22 without varying fromthe scope of the invention.

As with seal 28, seal 30 may be of any type capable of forming areliable, pressure tight seal between insert 16 and receptacle 22, butit is preferred that seal 30 be of a type that allows quick assembly ofreactor 10. An example being an elastomeric O-ring, or set of O-rings toengage between insert 16 and receptacle 22. However, most elastomericO-ring seals have a maximum temperature limitation that is lower thanthe bubble point of most liquid feeds that will be introduced to reactor10.

4. Evaporator—Evaporation Zone

Because of bubble points higher than maximum seal limitations, mostliquid feeds cannot be vaporized upstream of reactor 10 because theirelevated temperatures would compromise the integrity of seals 28 and 30.To solve this problem, an evaporator 44 is placed within reactor 10,downstream of seal 30 so that the maximum temperature limitation is notreached at seal 30.

Integrating an evaporator within reactor 10 has some inherent problemsthat need to be overcome in order for evaporator 44 to be effective, andprovide a vaporized gas stream with a constant and uniform composition.One of these problems is non-uniform mixing of a gas feed and liquidfeed, and another is non-uniform vaporization of a liquid feed. If thecomposition of the gas entering reaction zone 26 is not uniform, it willcreate unreliable results. With one main purpose of reactor 10 being theevaluation of catalysts, unreliable results would yield unreliable dataon catalyst 24 for the reaction in question.

One problem associated with evaporators in general is non-uniform mixingof a liquid feed and a gas feed. One way non-uniform mixing occurs iswhen both a gas and a liquid are introduced to an evaporator through acommon inlet. The combined feed of liquid and gas causes alternatingregions of gas entrainment and liquid pulsation being introduced to anevaporator, and therefore regions of low concentration of the vaporizedspecies followed by regions of high concentration of the vaporizedspecies being sent to a reactor bed.

Another problem associated with evaporators in general is non-uniformvaporization which occurs mainly because of a non-uniform flow of liquidinto an evaporator. In the case of slower moving flow, a liquid issuingfrom an orifice into an evaporator can form droplets that detach at aregular periodicity because of the fluid dynamics of the liquid. Theperiodic formation and detachment of droplets leads to non-uniformvaporization within the evaporator.

A stream of liquid issuing out of an orifice can become unstable due tocapillarity. This instability results in the formation of drops the sizeof which can be accurately predicted by linear stability analysis. Thecharacter of the liquid breakup at the orifice is primarily controlledby the Weber number, We: ${We} = \frac{\rho\quad{DU}^{2}}{\sigma}$where D is the diameter of the orifice, U is the average liquidvelocity, ρ is the liquid density and σ is the surface tension. TheWeber number expresses the balance between external kinetic force andsurface force, wherein the external force on the droplet is defined by:$F_{D} = {\frac{\rho\quad U^{2}}{2} \cdot \frac{\pi\quad D^{2}}{4}}$and the surface force of the droplet is defined by:F _(S) =πDσThe free interface of the droplet is stable when F_(D)<F_(S) or:${{\frac{\rho\quad U^{2}}{2} \cdot \frac{\pi\quad D^{2}}{4}} < {\pi\quad D\quad\sigma\quad{We}}} = {\frac{\rho\quad{DU}^{\quad 2}}{\sigma} < 8}$

When the Weber number is less than 8, a stable interface is created anduniform axi-symetric droplets form at the orifice. In the case ofreactor 10, liquid is introduced to evaporator 44 at low liquid flowrates, which result in low liquid velocities. For reactor 10, it is notuncommon to have Weber numbers that are much less than one. At very lowWeber numbers the droplets approach static equilibrium conditions, andthe droplet diameter can be very accurately predicted using theYoung-LaPlace equation:${\left( \frac{\pi\quad s^{3}}{6} \right){g\left( {\rho_{L} - \rho_{G}} \right)}} = {\pi\quad D\quad\sigma}$where s is the predicted diameter of the droplet, g is the accelerationof gravity, ρ_(L) is the density of the liquid, ρ_(G) is the density ofthe gas, D is the diameter of the orifice and σ is the surface tensionof the liquid.

The droplet volume and liquid flow rate allow the estimation of dropletdetachment times, in the case of reactor 10 of between about 4 and about6 seconds. The periodic detachment of droplets leads to severemalfunctioning patterns of vapor concentrations associated withnon-uniform vaporization of the droplets.

In the inventive evaporator 44 of the present invention, the problem ofnon-uniform mixing is solved by feeding the liquid feed and gas feed atdifferent locations within insert 16 so that mixing occurs between thegas feed and liquid feed in evaporation zone 18, not in injector 48.Liquid feed enters insert 16 through orifice 66 of injector 48, whereorifice 66 is a substantial distance down the length of insert 16, whilegas feed enters insert 16 near inlet end 72 of insert 16. Preferably,orifice 66 is located within evaporation zone 18.

To prevent periodic droplet formation and detachment, and thereby solvethe problem of non-uniform vaporization, at least one evaporationsurface, such as surfaces 82 of packing 76, is placed within theinventive evaporator 44 of the present invention relative to orifice 66of injector 48 to interfere with the formation of droplets.

Evaporation surfaces other than those on packing 76 as described may besuccessfully employed in the present invention. Examples of suchevaporation surfaces include, but are not limited to, plates, a porousmonolith, a cone, and the like. The selected evaporation surface ispositioned to prevent the formation of a droplet at orifice 66 ofinjector 48. The description herein will exemplify the preferredembodiment where the evaporation surfaces are surfaces 82 of packing 76,however, one of ordinary skill in the art would readily understand theinvention as employing other suitable evaporation surfaces.

Bed 78 provides an evaporation zone 18 necessary to effectively vaporizethe liquid feed. Evaporation zone 18 is encased within housing 12. FIG.4 shows a close up view of injector 48 and packing 76 at the point wherethe liquid feed is injected into bed 78. Injector 48 includes orifice 66with a diameter D at its terminal end. Liquid feed flows throughinjector 48 at a average liquid flow rate, U, that would result in theperiodic formation of a droplet 88 with a diameter, s, as shown in FIG.4, where s is determined by the Young-LaPlace equation. Packing 76 isplaced in close proximity to orifice 66, defining a gap 90 betweenorifice 66 and packing 76. It has been hypothesized that if gap 90 issufficiently smaller than the predicted diameter s of droplet 88, thenpacking 76 will interfere with the formation of a stable interface anddroplet 88 is not allowed to form. Instead, the liquid feed forms a thinliquid film 84 on the surfaces 84 of packing 76 allowing uniformvaporization of the liquid feed. Because of the uniform vaporization, aconstant concentration of vapor is contacted by catalyst 24, resultingin accurate results obtained by reactor 10. It is preferred that gap 90be minimized to be as small as possible without plugging orifice 66 toensure that packing 76 interferes with the creation of a stableinterface of droplet 88.

Unexpectedly, a minimized gap 90 between packing 76 and orifice 66 ininventive evaporator 44 of the present invention is so effective thatattempts to reproduce non-uniform vaporization by setting evaporatorheater 20 low enough so that the temperature of the liquid feed is belowits bubble point until well into bed 78 were unsuccessful. Nomalfunctioning concentration patterns were created by evaporator 44,despite the attempt to artificially produce them.

In order to ensure adequate flow distribution over packing 76 in bed 78,it is important to use appropriate sizes of packing 76. Diameters ofpacking 76 should be small enough to avoid a “wall effect” of the liquidflowing along the inner surface of insert 16. Preferably, the maximumdiameter of packing 76 should be less then about 10% of the insidediameter of insert 16 to avoid wall flow. However, the minimum diameterof packing 76 should be larger than the diameter of orifice 66 toprevent clogging of orifice 66 by particles of packing 76. In oneembodiment, the diameter of packing 76 may be between about 0.21 mm andabout 0.42 mm. However, packing 76 is not limited to the abovedimensions and could be scaled up or down without varying from the scopeof the present invention.

Evaporator 44 of reactor 10 is not limited to use in a reactor.Evaporator 44 itself is novel and inventive and provides an improvementover previous evaporators. The inventive evaporator 44 of the presentinvention could also be used in another process vessel where it isdesirable to vaporize a liquid feed, followed by further processing in atreatment zone within the same process vessel. The process vessel wouldhave both an evaporation zone and a treatment zone, with the evaporationzone including the inventive evaporator 44. In the case of the presentinvention, reactor 10 is the process vessel and reaction zone 26 is thetreatment zone of the vapor.

5. Evaporator Heater

Evaporator heater 20 provides the necessary energy to vaporize liquidfeed within bed 78. Evaporator heater 20 is associated with a portion ofreactor 10. Preferably, evaporator heater 20 is associated primarilywith evaporation zone 18 at the point where the liquid feed is injectedinto bed 78 as shown in FIG. 3, although other locations may besuccessful as well. The duty of evaporator heater 20 is preferablyprovided by electrical resistive heating adjacent to housing 12.Evaporator heater 20 could be a heater block with a thickness largerthen the diameter of housing 12 so that evaporator heater 20 is placedaround housing 12 housing 12. However, evaporator heater 20 could be anyother type of heater, such as one utilizing a heat transfer fluid, andwould not vary from the scope of the invention.

Evaporator heater 20 is set at a temperature sufficient to vaporize theliquid feed within evaporation zone 18, forming a vapor. Preferably, thetemperature of the liquid feed at orifice 66 is below its bubble point,and evaporator heater 20 is set so that the liquid feed is heated toabove its bubble point within evaporation zone 18, creating atemperature gradient within evaporation zone 18. Still more preferably,evaporator heater 20 is set so that a temperature gradient is createdthroughout evaporation zone 18 so that the temperature of the vapor isheated to a predetermined reaction temperature within evaporation zone18 before the vapor enters reaction zone 26.

In one embodiment, the thickness of evaporator heater 20 may be about 8mm. However, evaporator heater 20 is not limited to the above dimensionsand could be scaled up or down without varying from the scope of thepresent invention.

6. Receptacle

Referring to FIG. 3, receptacle 22 is placed within housing 12, andinsert 16 is placed within receptacle 22 in a nested configuration sothat seal 28 is engaged between header 14 and shoulder 36 of housing 12and seal 30 is engaged between insert 16 and receptacle 22. Receptacle22 is preferably removable. Receptacle 22 includes an inlet end 94 andan outlet end 96. A flange 98 is attached to inlet end 94. Flange 98 ofreceptacle 22 includes cut-out sections 102 (See FIG. 2) to allow adiluent gas to pass through. The diluent gas passes through cut-outsections 102 in flange 98 and into a fluid path 68 formed betweenreceptacle 22 and main section 38 of housing 12.

Receptacle 22 retains catalyst 24, within reaction zone 26. It is withinreaction zone 26 that the gas feed and the vapor are contacted, atreaction conditions, with catalyst 24, where they are reacted to form aproduct. A fluid permeable member 104 is attached at outlet end ofreceptacle 22 to retain catalyst 24, but allow fluids, such as unreactedfeeds and product gas, to pass out of receptacle 22 and exit reactor 10out of product conduit 40. Fluid permeable member 104 is preferably asintered metal, such as Hastelloy, but could be any material that ispermeable to the fluids passing out of receptacle 22 and sufficientlystrong to support catalyst 24. Other possible materials of fluidpermeable member 104 include glass, sintered glass, Raney metals,electro-bonded membranes, etched alloy membranes, and fine meshedscreens with gaps that are smaller than the size of catalyst 24, butlarge enough to allow the unreacted feeds and product gas to flowadequately.

Catalyst 24 is selected to provide active sites for the desiredreaction. Catalyst 24 may be any material or mixture of materials thatpossibly catalyze the desired reaction, but preferably catalyst 24 is azeolite or some other type of catalyst that can be synthesized bycombinatorial methods. In one embodiment, an effective mass of catalyst24 placed within receptacle 22 of reactor 10 may range from about 1 mgto about 1 gram. However, catalyst 24 is not limited to the abovemasses, and more or less catalyst 24 could be added to reactor 10without varying from the scope of the present invention.

Reaction zone 26 is flanked by fluid permeable members 80 and 104upstream and downstream of catalyst 24 and by inner surface 106 ofreceptacle 22 on the side so that catalyst 24 remains within reactionzone 26. Reaction zone 26 has the same diameter as the inside diameterof receptacle 22. In one embodiment, reaction zone 26 may have a heightof between about 1.0 cm and about 1.5 cm.

Receptacle 22 is preferably of the same general shape as housing 12 andinsert 16 so that receptacle 22 may easily fit between housing 12 andinsert 16 within predetermined tolerances. Receptacle 22 is preferablycylindrical in shape, but may be of another geometric shape. For ease ofdiscussion, receptacle 22 is described as a cylinder having a length anda diameter. The length of receptacle 22 is approximately the same as thelength of main section 38 of housing 12. The lengths of insert 16 andreceptacle 22 are chosen so that reaction zone 26 has its desiredheight. The diameter of receptacle 22 is chosen so that fluid path 68 isprovided between receptacle 22 and housing 12 to allow the diluent gasto bypass reaction zone 26 as shown in FIG. 3. Fluid path 68 may also beformed by channels or groves in receptacle 22 or housing 12 to allow thediluent gas to bypass reaction zone 26. In one embodiment, receptacle 22may have a length of between about 10 cm and about 14 cm and a diameterof between about 0.4 cm and about 0.5 cm.

The diameter of flange 98 of receptacle 22 is preferred to beapproximately the same as the diameter of shoulder 36 of housing 12. Inone embodiment, the diameter of flange 98 of receptacle 22 may be about0.8 cm.

Receptacle 22 and reaction zone 26 are not limited to the abovedimensions and could be scaled up or down without varying from the scopeof the present invention.

Receptacle 22 is preferably constructed out of a material that is inertto reaction with the liquid and gas feeds, is resistant to corrosion,can withstand temperatures of from about 10° C. to about 1000° C., andhas good heat transfer properties. It is preferred that receptacle 22 beconstructed of a similar, or identical material as housing 12 and insert16. Examples of suitable materials of construction include metals andtheir alloys, low grade steel, stainless steels, super-alloys likeIncolloy, Inconel, Hastelloy, engineering plastics and high temperatureplastics, ceramics such as silicon carbide and silicon nitride, glass,and quartz. A preferred material of construction of receptacle 22 is 321stainless steel.

7. Reaction Heater

A reaction heater 108 is placed adjacent to housing 12 so that it isassociated primarily with reaction zone 26 and so that all of reactionzone 26 is surrounded by reaction heater 108. Reaction heater 108provides heat for reaction zone 26 so that catalyst 24 and reaction zone26 can be maintained at a controlled constant temperature. Reactionheater 108 can be any type of heater to provide the heat needed forreaction zone 26, such as an aluminum-bronze oven using electricalresistive heating.

As shown in FIG. 3, reaction heater 108 is placed around outlet end ofhousing 12 so that all of reaction zone 26 is within the oven. In oneembodiment, reaction heater 108 may have a thickness of about 9 cm andthe length of reactor 10 that is within reaction heater 108 may bebetween about 4 cm and about 6 cm. However, reaction heater 108 is notlimited to the above dimensions and could be scaled up or down withoutvarying from the scope of the present invention.

Preferably, the length of reactor 10 that is between evaporator heater20 and reaction heater 108 is sufficient so that the temperature atpacking 76 is substantially independent of the temperature at catalyst24. The temperature of the liquid feed at orifice 66 of injector 48should not be affected by how reaction heater 108 is set, and thetemperature within reaction zone 26 should not be affected by howevaporator heater 20 is set. In one embodiment, the length of reactor 10between evaporator heater 20 and reaction heater 108 may be betweenabout 2.5 cm and about 8 cm, but reactor 10 is not limited to thisdimension and could be scaled up or down without varying from the scopeof the present invention.

8. Diluent Gas and Diluent Zone

Some reaction mixtures of reactor 10 include a liquid feed or a productthat has a high dew point. This creates a problem for a product mixtureexiting reactor 10 through outlet end after leaving reaction heater 108because the temperature of the reaction mixture decreases to below themixture's dew point, causing liquid feed or product to condense out ofthe gas phase. For some products, not only is the dew point high, but sois a freezing point, so that not only does the product condense out ofthe gas phase, but it also forms a solid, or plates along productconduit 40. Condensing or plating of product causes two problems. First,it can block or obstruct flow through product conduit 40, and second, italters the gas phase composition of the product stream. Because it isthe gas phase composition that is measured by analyzing downstream ofreactor 10, condensation or plating can adversely impact experimentalresults determined by reactor 10.

It has been verified that the addition of a diluent gas to reactor 10allows for a reduction in pressure for analysis of product, whilepreventing the condensation and plating of product. As shown in FIG. 3,diluent gas is introduced through diluent gas inlet 52 of header 14. Thediluent gas then passes through cut-out sections 102 in flange 98 ofreceptacle 22 where it flows into fluid path 68 between receptacle 22and main section 38 of housing 12 so that the diluent gas bypassescatalyst 24. Fluid path 68 is in fluid communication with diluent gasinlet 52 and diluent gas mixing zone 110. Fluid path 68 may be formeddue to a difference in diameter between housing 12 and receptacle 22, asshown in FIG. 3, or housing 12 and receptacle 22 may have a smalltolerance between them and fluid path 68 may be formed by grooves orchannels in either housing 12 or receptacle 22. Grooves or channels (notshown) may also provide for more efficient heat transfer between thediluent gas and evaporation zone 18 and reaction zone 26.

The diluent gas dilutes product and unreacted feeds in mixing zone 110downstream of reaction zone 26 and fluid permeable member 104 ofreceptacle 22 near outlet 34 of housing 12. The addition of diluent gasdilutes the product stream in mixing zone 110, lowering theconcentration and partial pressure of trace undesirable by-products inthe reactor effluent, thus preventing condensation and/or plating andsubsequent equipment fouling.

The diluent gas may be mixed with the product stream at any pointdownstream of reaction zone 26, but it is preferred that it be mixedbefore product conduit 40 exits reaction heater 108 so that there is nopossibility of condensation or plating of product.

The diluent gas may be any gas capable of mixing with the productstream. It is preferred that the diluent gas be the same as the gas feedso that both the gas feed and the diluent gas may be introduced toreactor 10 from a common gas reservoir. Like the liquid feed and the gasfeed, diluent gas is introduced to reactor 10 in a measured amount andwith a known composition so that the amount of each component beingmixed with the product gas is known.

9. Sampling and Analyzing

Reactor 10 is used to evaluate catalysts by determining their activityand selectivity. To accomplish this, at least a portion of the productgases flowing through product conduit 40 is analyzed by an analyzer 112to determine its chemical composition. In one embodiment, a portion ofthe product is sampled prior to analyzation by analyzer 112. The flowrate of product in product conduit 40 is also measured so that theamount of each species exiting reactor 10 can be determined. Analyzer112 can use any method to determine each product gasses composition, butpreferably uses one of the following analytic techniques; spectroscopy,spectrometry, chromatography, nuclear magnetic resonance, or acombination thereof.

10. Alternative Embodiment with Cooler

Seals 28 and 30 and both have a maximum temperature limitation that islower than the bubble point of many liquid feeds that will be introducedto reactor 10. In an alternative embodiment of reactor 10, shown in FIG.5, a cooler 114 is added to maintain a temperature at seals 28 and 30 toensure that seals 28 and 30 are not compromised. Cooler 114 is placedadjacent to housing 12 between evaporator heater 20 and header 14,preferably so that cooler 114 is adjacent to both seals 28 and 30.Cooler 114 is set so that the temperature of seals 28 and 30 is belowtheir maximum temperature limitation, ensuring that seals 28 and 30 arenot compromised.

Cooler 114 may be of any type capable of removing the heat necessary tomaintain seal temperatures below the maximum temperature limitation, butit is preferred that cooler be a plate heat exchanger cooled with waterflowing through a conduit within plate 116. Plate 116 of cooler 114 maybe made of any heat conducting material, but aluminum is preferred. Inone embodiment the thickness of plate 116 of cooler 114 may be about 1cm and the diameter of the cooling water conduit (not shown) withinplate 116 may be about 0.0625 inches. However, cooler 114 is not limitedto the above dimensions and could be scaled up or down without varyingfrom the scope of the present invention.

B. Process of Evaporating and Reacting in a Reactor

The process by which reactor 10 vaporizes a liquid feed and reacts theresulting vapor in the presence of catalyst 24 includes the steps ofproviding packing 76 in evaporation zone 18, providing catalyst 24 inreaction zone 26, introducing a liquid feed to evaporation zone 18,heating and vaporizing the liquid feed within evaporation zone 18 toform a vapor, flowing the vapor into reaction zone 26, and contacting,at predetermined reaction conditions, the vapor with catalyst 24 to forma product. In some cases a gas feed may also be introduced to reactor 10so that both the gas feed and the vapor are contacted with catalyst 24in reaction zone 26 to react and form a product.

The liquid feed may be any liquid component or mixture of liquidcomponents, that is able to be vaporized under a predetermined range oftemperatures and pressures and may undergo a reaction that may becapable of being catalyzed by catalyst 24. The liquid feed is preferredto be a liquid hydrocarbon. Examples of hydrocarbon intended for the usein reactor 10 are aromatic, aliphatic, and naphthene compounds havingsix or more carbon atoms, preferably six to nine carbon atoms. Examplesof intended feed components are benzene, toluene, xylenes, ethylbenzenes, cumene, higher alkyl substituted benzenes, cyclohexanes,cyclopentanes, higher alkyl substituted cyclic paraffins, pentane,hexanes, heptanes, octanes, nonanes, decanes, and higher molecularweight aliphatics and mixtures of the above. Alternatively, the liquidfeedstock may be or may contain one or more components having hydrogen,carbon, and another element such as oxygen, chlorine, sulfur, nitrogen,and the like.

It is preferred that the chemical composition of the liquid feed beknown and that the liquid feed be introduced to reactor 10 in a measuredamount so that calculations can be performed to determinecharacteristics of catalysts 24 such as activity, feed conversion, majorproduct and byproduct selectivities and yields.

The gas feed may be any gas that may undergo a reaction that is capableof being catalyzed by catalyst 24, or that may provide a stabilizingeffect on the catalyst, and could be an organic or inorganic gas.Examples of gas feeds are hydrogen gas, oxygen gas, nitrogen gas orlight hydrocarbons in the gas phase such as methane or ethane. It ispreferred that the chemical composition and flow rate of the gas feedinto reactor 10 feed be known so that calculations can be performed todetermine an activity and selectivity for catalyst 24 as describedbelow.

In one process, catalyst receptacle 22 is placed containing catalyst 24for reacting vaporized feed within housing 12 where receptacle 22 ispositioned within reactor 10 so that catalyst 24 is within reaction zone26, insert 16 is placed containing packing 76 having surfaces 82 forevaporating feed where insert 16 is positioned within receptacle 22 sothat packing 76 is within evaporation zone 18, the liquid feed isinjected into evaporation zone 18 through injector 48 in a measuredamount, where it passes through header 14 and into insert 16. Next,liquid feed is injected through orifice 66 in injector 48 into bed 78formed by packing 76, and forms a thin liquid film 84 on the surfaces 82of packing 76.

After the liquid feed is injected into bed 78 and forms thin liquid film84, the liquid feed is heated by evaporator heater 20 which is situatedso that the liquid feed is heated at or near orifice 66. Evaporatorheater 20 is set at a temperature sufficient to vaporize the liquid feedwithin evaporation zone 18, forming a vapor. Preferably, the temperatureof the liquid feed at orifice 66 is below its bubble point, andevaporator heater 20 is set so that the liquid feed is heated to aboveits bubble point within evaporation zone 18, creating a temperaturegradient within evaporation zone 18. Still more preferably, evaporatorheater 20 is set so that a temperature gradient is created throughoutevaporation zone 18 so that the temperature of the vapor is heated to apredetermined reaction temperature within evaporation zone 18 before thevapor flows into reaction zone 26.

Packing 76 is provided and placed in insert 16 so that there is a gap 90defined between orifice 66 and packing 76 that is sufficiently small tointerfere with the formation of a droplet on injector 48 at orifice 66.Instead of forming a liquid droplet, the liquid feed forms a thin liquidfilm 84 on surfaces 82 of packing 76 which is easily vaporized. Heatprovided by evaporator heater 20 vaporizes the liquid feed within bed 78before it enters reaction zone 26 to contact catalyst 24 and react.After being heated and vaporized, the resulting vapor flows through theremainder of evaporation zone 18 and passes through fluid permeablemember 80 and into reaction zone 26.

If a gas feed is to be introduced to reactor 10, it is introducedthrough header 14 in a measured amount and enters insert 16 at somepoint upstream of orifice 66. The gas feed is then mixed with the vaporin evaporation zone 18 and acts as a carrier gas for the vapor as theypass down the remainder of bed 78, through fluid permeable member 80 andinto reaction zone 26.

After entering reaction zone 26, the vaporized hydrocarbon feed and thegas feed, if present, as well as catalyst 24 are heated by reactionheater 108 to a predetermined reaction temperature. Reaction heater 108provides the heat requirement, to maintain a constant, predetermined andcontrolled temperature in reaction zone 26. To control the temperatureof reaction zone 26, the temperature of reaction zone 26 is constantlymeasured by thermocouple 54. This measured temperature is then used tocontrol the setting of reaction heater 108. For example, if thetemperature measured by thermocouple 54 is too high, the actualtemperature is compared with a specified temperature to create an errorbetween the two, and this error is used to lower the heater blockset-point.

After passing through fluid permeable member 80 in insert 16 intoreaction zone 26, the vaporized hydrocarbon and the gas feed quicklyreach the predetermined temperature. The vapor and gas feed arecontacted with catalyst 24 and go through at least one reaction togenerate a product mixture of a product, byproducts, and unreactedfeeds. The product mixture then flows out of reaction zone 26 throughfluid permeable member 104 and into product conduit 40, where it iscarried away from reactor 10.

A portion of the product mixture is sampled and analyzed by analyzer 112to determine its chemical composition. The product mixture may beanalyzed by any of the following analytic techniques; spectroscopy,chromatography, nuclear magnetic resonance, and combinations thereof.

In an alternate embodiment, reaction heater 108 may provide sufficientheat to also heat the packing 76 in evaporation zone 18. With the heatfor the packing 76 being provided by reaction heater 108, a gradient ofheat may be established across packing 76. The amount of heat providedto the packing 76 may be controlled by the positioning of reactionheater 108 and the distance between reaction zone 26 and packing 76.

As described above, in some cases it may be desirable to dilute theproduct mixture with a diluent gas after the product has been formed inreaction zone 26 to suppress the partial pressure of one or morecomponents in the product mixture and prevent condensation into theliquid phase or plating into the solid phase. Preferably, the diluentgas is the same gas as the gas feed so that they may be introduced froma common reservoir. It is preferred that the chemical composition andflow rate of the diluent gas into reactor 10 be known so thatcalculations can be performed to determine an activity, feed conversion,major product and byproduct selectivities and yields for catalyst 24.

If it is desired, the product mixture is diluted with diluent gas inmixing zone 110 after the product mixture has passed through fluidpermeable member 104. The diluent gas may be introduced by any number ofmethods but it is preferred that the diluent gas be introduced toreactor 10 in a measured amount and bypass reaction zone 26 so that thediluent gas does not come in contact with catalyst 24. Feeding thediluent gas to reactor 10 is desirable so that the inlets for the liquidfeed, the gas feed and the diluent gas will all be introduced to theapparatus at the same general location. However, diluent gas could beintroduced to product mixture by a different method, such as a separateconduit that is in fluid communication with mixing zone 110 of fluidpermeable member 104.

After the diluent gas is introduced to product mixture, it quickly mixeswith the product mixture in mixing zone 110 in product conduit 40 tosuppress partial pressures of the components of the product mixture andforms a diluted product mixture. At least a portion of the dilutedproduct mixture is sampled and analyzed by 112 as described above.

C. Array of Multiple Reactors

Although reactor 10 by itself is an inventive and novel reactor forvaporizing a liquid feed and reacting the resulting vapor in thepresence of catalyst 24, it is when an array 120 of two or more reactors10 is formed and operated in parallel that the present inventionprovides the fullest range of utility. An array 120 of reactors 10operated in parallel allows catalyst 24 to be tested at severaldifferent reaction conditions, or a plurality of different catalysts 24to be compared, or a plurality of feeds or feed compositions to becontacted with catalysts 24, or a combination thereof, so that theactivity and selectivity of each catalyst 24 can be calculated forvarious conditions, so that the most effective catalyst, and the optimalconditions for that catalyst, can be determined for the reaction ofinterest.

As shown in FIG. 6, an array 120 of two or more reactors 10 is provided.Each of the reactors 10 of array 120 have all of the elements describedabove for reactor 10, a housing 12, a header 14, an insert 16 forretaining packing 76 that forms a bed 78 within evaporation zone 18, anda receptacle 22 for retaining catalyst 24 that forms a reaction zone 26.Each reaction zone 26 can consist of the same catalyst 24, and reactors10 in array 120 can be operated at different reaction conditions, or aplurality of different catalysts 24, or blocks of catalysts 24, can beplaced in the reaction zones 26 to compare a plurality of catalysts 24.However, only one evaporator heater 20 is provided to heat the liquidfeed at the orifices 66 of the injectors 48 in each reactor 10.Evaporator heater 20 is placed so that it is associated with each of theoutside surfaces 92 of each of the housings 12 in array 120.

Reactors 10 in array 120 are intended to perform the same reaction sothat common liquid feed, gas feed, and diluent gas is introduced to eachreactor 10 in array 120. The liquid feed, gas feed and diluent gas areintroduced to reactors 10 simultaneously so that reactors 10 operate inparallel allowing several catalysts 24, or several reaction conditions,to be evaluated simultaneously, greatly decreasing the experimental timerequirement associated with testing multiple catalysts 24 at multiplereaction conditions by conventional methods.

1. Each Housing Attached to a Bottom Support Plate

Each housing 12 of array 120 can be a free-standing unit with thefeatures of housing 12 described above, or the housings 12 can be formedfrom a single tray or block of material. It is preferred that housings12 be free-standing units so individual housings 12 may be replaced asneeded due to damage or change-out. But, it is also preferred thathousings 12 be connected to a common bottom support 122 so that theplurality of housings 12 in array 120 can be moved as a single unit, asit is far more convenient to handle an assembly of one unit than toindividually manipulate multiple housings 12. Also, robotics, which isfrequently used in combinatorial applications, is more readily adaptedto manipulating a single tray. It is preferred that each housing 12 inarray 120 be constructed of the same material, but it is not necessary.Housings 12 can be constructed of the same materials as housing 12described above. It is further preferred that inserts 16 and receptacles22 be constructed of the same material as housings 12.

Bottom support 122 may provide for the connection of any number ofindividual housings 12. For example, bottom support 122 may connect to6, 8, 12, 24, 48, 96 or 384 of housings 12. Also, the full capacity of aparticular bottom support 122 need not be used. For example, a bottomsupport 122 designed to hold up to 48 of housings 12 may be used tosupport only 24. Array 120 is flexible in this respect, because thenumber of reactors 10 being used by array 120 can be changed simply byadding or taking away a desired number of housings 12 from bottomsupport 122.

Bottom support 122 could be any shape or configuration capable ofsupporting the plurality of housings 12 in a desired, predeterminedpattern, but it is preferred that bottom support 122 be a plate withholes for each corresponding housing 12. As shown in FIG. 6 and FIG. 7,the plate of bottom support 122 includes a surface 124 which isgenerally planar.

As with the housing 12 itself, bottom support 122 may be constructed ofa variety of materials including metals and their alloys, low gradesteel, and stainless steels, super-alloys like Incolloy, Inconel andHastelloy, engineering plastics and high temperature plastics, ceramicssuch as silicon carbide and silicon nitride, glass, quartz, Teflonpolymer, nylon, and low temperature plastics such as polyethylene, andpolypropylene. It is preferred that bottom support 122 be rigid enoughto resist twisting from torque so that bottom support 122 remainssubstantially planar throughout operation of array 120.

Bottom support 122 may allow for the connection of housings 12 in anynumber of geometrical patterns with the preferred being a grid. It ispreferred that bottom support 122 has dimensions similar to thedimensions of commonly used micro titer trays. It is preferred thatbottom support 122 be constructed of material that is able to withstandtemperatures of from about 10° C. to about 1000° C., and for manycatalytic reactions, bottom support 122 may be required to withstandtemperatures ranging from about 0° C. to about 1000° C.

2. Each Header Attached to a Top Support Plate

Each housing 12 of array 120 has a corresponding insert 16 and header 14that has all of the features of insert 16 and header 14 described above.Each of the headers 14 are connected to a top support 126 so that eachhousing 12 has a corresponding insert 16 placed inside the housing 12 toenclose the plurality of reactors 10 in array 120. Headers 14 areconnected to top support 126 so that the plurality of headers 14 andinserts 16 can be moved as a single unit, as it is far more convenientto handle an assembly of one unit than to individually manipulatemultiple inserts 16. Also, because housings 12 are connected to bottomsupport 122 and headers 14 are connected to top support 126, theplurality of headers 14 and inserts 16 can be moved as a single pieces,allowing array 120 to be assembled by one step which simultaneouslyseals to form array 120.

It is preferred that each header 14 and each insert 16 of array 120 beconstructed of the same material, but it is not necessary. Inserts 16may be constructed from the same materials as header 14 and insert 16described above. In some applications it may be preferred for headers 14and inserts 16 to be constructed from the same material, or similarmaterial, as the corresponding housings 12.

Top support 126 may provide for the connection of any number ofindividual headers 14. For example, top support 126 may connect to 6, 8,12, 24, 48, 96 or 384 of headers 14. Also, the full capacity of aparticular top support 126 need not be used. For example, a top support126 designed to hold up to 48 of headers 14 may be used to support only24. Array 120 is flexible in this respect, because the number ofreactors 10 being used by array 120 can be changed easily simply byadding or taking away a desired number of headers 14 and inserts 16 fromtop support 126.

Top support 126 could be any shape or configuration capable ofsupporting the plurality of inserts 16 in a desired, predeterminedpattern, but it is preferred that top support 126 be a plate with holesfor each corresponding header 14. As shown in FIG. 6 and FIG. 7, theplate of top support 126 includes a surface 128 which is generallyplanar.

As with header 14 and insert 16, top support 126 may be constructed of avariety of materials including metals and their alloys, low grade steel,and stainless steels, super-alloys like Incolloy, Inconel and Hastelloy,engineering plastics and high temperature plastics, ceramics such assilicon carbide and silicon nitride, glass, quartz, Teflon polymer,nylon, and low temperature plastics such as polyethylene, andpolypropylene. It is preferred that top support 126 be rigid enough toresist twisting torque so that top support 126 remains substantiallyplanar throughout operation of array 120.

Top support 126 may allow for the connection of inserts 16 in any numberof geometrical patterns with the preferred being a grid. It is preferredthat top support 126 has dimensions similar to the dimensions ofcommonly used micro titer trays. It is preferred that top support 126 beconstructed of a material capable of withstanding temperatures from 10°C. to about 1000° C., but a preferred range of temperatures includestemperatures ranging from about 10° C. to about 300° C.

3. Receptacles

Each set of housings 12 and corresponding inserts 16 has a correspondingreceptacle 22 for retaining catalyst 24 having the features of thereceptacle 22 described above to form a reactor 10 within array 120.Each reactor 10 is assembled in the same manner as described above,except that each reactor 10 is connected to a set of supports 122 and124 to form array 120.

It is preferred that each receptacle 22 of array 120 be constructed fromthe same material, but it is not necessary. In some case it may also bepreferred for the receptacle 22 to be constructed from the samematerial, or a similar material, as the housing 12, or the samematerial, or a similar material, as the insert 16, or both.

4. Quick Connect System Including Quick Sealing

Array 120 of reactors 10 allows for the rapid evaluation of multiplevariables simultaneously. For example, each reactor 10 of array 120 canbe used to evaluate a different catalyst 24 under the same reactionpressure and temperature and with the same feed compositions, or eachreactor 10 can evaluated the same catalyst 24 under varying reactionconditions, such as multiple pressures, temperatures and feed rates andcompositions. To fully realize the greatest utility, it is preferredthat array 120 include an apparatus that allows for the quick assemblyand disassembly of array 120. Seals 28 and 30 aid in this quick-connectbecause they allow each reactor 10 to be assembled quickly, but stillprevent leaks between parts of the reactor and between reactor 10 andits environment. Each seal 28, 30 operates to seal the plurality ofreactors 10 simultaneously. Housing support 122 is important because itallows the plurality of housings 12 to be moved as a single piece andinsert support 126 is important because it allows the plurality ofheaders 14 and inserts 16 to be moved as another single piece. However,an apparatus is still needed to raise and lower housing support 122 andinsert support 126.

Quick-connect system 130 provides a method to raise and lower supports122 and 126 while still assuring high precision in the horizontal plane,allowing seals 28 and 30 to seal effectively in each reactor 10.Quick-connect system 130 can be used to raise and lower housing support122 with insert support 126 remaining stationary, or it can be used toraise and lower insert support 126 with housing support 122 remainingstationary, or each support can have its own quick-connect system andboth supports 122 and 126 can be raised and lowered as desired. For easeof discussion, quick-connect system will be described as being used toraise and lower insert support 126 while housing support 122 remainsstationary, as shown in FIG. 7, but as discussed above quick-connectsystem 130 could be used for either support 122 or 126.

One embodiment of quick-connect system 130 includes threaded guide rods132, guide rings 134, stationary rings 136 and wheels 138. Guide rings134 are attached to insert support 126 so that they extend away frominsert support 126. In FIG. 7, a set of two guide rods 132 are shown,each guide rod 132 having a corresponding guide ring 134, stationaryring 136 and wheel 138. Although two of each of the pieces is shown inFIG. 7, any number could be used without varying from the scope of thepresent invention.

Each guide rod 132 is threaded so that when it is rotated insert support126 will be raised or lowered depending on which direction guide rod 132is rotated. Each guide ring 134 includes a hole 140 that is generally inthe center of guide ring 134. It is preferred that hole 140 be generallycylindrical in shape and extend through guide ring 134. Hole 140 is alsothreaded so that a corresponding threaded guide rod 132 can be placedthrough hole 140. Guide rod 132 and hole 140 are threaded so that whenguide rod 132 is rotated, guide ring 134, and therefore insert support126, is moved up or down depending on which direction guide rod 132 isrotated.

Each hole 140 includes an inside surface (not shown). It is preferredthat the inside surface of hole 140 be generally perpendicular tosurface 128 of insert support 126 so that when insert support 126 israised and lowered surface 128 of insert support 126 remains parallel tosurface 124 of housing support 122. This perpendicular raising andlowering of insert support 126 is preferred because it ensures thatseals 28 and 30 of each reactor 10 engage simultaneously when eachinsert 16 is lowered into its corresponding housing 12-receptacle 22combination as insert support 126 is lowered. If surface 128 of insertsupport 126 did not remain parallel to surface 124 of housing support122 not every reactor 10 of array 120 would be sealed. Some of the seals28 and 30 would engage properly, while other seals 28, 30 would not comeinto contact with their corresponding housings 12 or receptacles 22 andwould fail to properly seal certain reactors 10. Still other seals 28and 30 could pinch or bind within their corresponding reactors 10,causing a problem when insert support 126 is attempted to be raisedbecause certain inserts 16 would stick within their correspondinghousings 12.

Each stationary ring 136 also includes a hole 142 for a correspondingguide rod 132 to pass through. Stationary ring 136 is anchored to astationary support 144 of array 120 so that it remains stationary whileguide rod 132 rotates. Stationary ring 136 keeps guide rod 132 inposition while it is rotated so that insert support 126 is raised andlowered instead of guide rod 132. Each hole 142 is threaded, like itscounterpart hole 140 in guide ring 134. Each hole 142 includes an insidesurface (not shown) that is preferred to be generally perpendicular tothe plane of surface 124 of housing support 122 so that surface 124 ofhousing support 122 and surface 128 of insert support 126 remainparallel throughout operation of quick-connect system 130. Stationaryring 136 could be anchored by any method to any stationary member ofarray 120, but it is preferred that it be anchored to something nearinsert support 126 so that guide rod 132 need not be excessively long.In one embodiment, stationary rings 136 are shown to be anchored byanchors 146 to support 144 of housing support 122, as shown in FIG. 7.

Each guide rod 132 has a corresponding wheel 138 which is used to rotateguide rod 132. Each wheel 138 is attached to an end of guide rod 132 andmay include a handle 148. If more than one guide rod 132 is used, asshown in FIG. 7, it is preferred that the rotation of guide rods 132 besynchronized to ensure that support 122 or 126 remains in a horizontalplane throughout operation of quick-connect system 130. A means thatcould accomplish this would be coupling the rods with a belt system (notshow) so that both guide rods 132 rotate the same amount at the sametime.

Although a quick-connect system 130 with guide rods 132, rings 134, 136and wheels 138 is described, the present invention is not limited to aquick-connect system 130 with these embodiments. Other means could beused to ensure that support plates 122 and 126 remain in a horizontalplane and remain parallel to each other, such as a precision rail guidesystem attached to support plates 122 and 126. One of ordinary skill inthe art will appreciate the many types of systems that could be used toraise and lower support plates 122 and 126 and still remain within thescope of the present invention.

Guide rods 132, guide rings 134 and stationary rings 136 can bepurchased from a supplier so that a predetermined precision can beprovided by quick-connect system 130. Examples are catalog numbers S151101900, S 151201023, S 150600010 and S 159111020 from Rexroth BoschGroup.

5. Common Feed Reservoirs

Array 120 also creates the need for fewer feed reservoirs to store feedliquids and gases to be introduced to the reactors 10 in array 120. Onlyone liquid feed reservoir 150 is required to introduce liquid feedthrough injectors 48 associated with each of the reactors 10 of array120 because each reactor 10 of array 120 is performing the samereaction, with the same liquid feed. Similarly, only one gas feedreservoir 152 is required to introduce feed to the gas feed inlets 50associated with each header 14. Also, if the diluent gas is the same gasas the gas feed, a third reservoir is unnecessary so that only liquidfeed reservoir 150 and a gas feed, reservoir 152 are required for theoperation of array 120. However, if a gas other than the gas feed isused as the diluent gas, a third reservoir (not shown) for the diluentgas would be required.

In some cases it may be desirable to introduce the liquid feed, gas feedand diluent gas to reactors 10 in array 120 in measured amounts so thatthe exact amount of each substance entering each reactor 10 is known. Itis desirable to do this because the combination of knowing how muchreactant or diluent gas is introduced to each reactor 10 and thecomposition of the product gas exiting each reactor 10 can be used tocalculate the activity, feed conversion, major product and byproductselectivities and yields for each catalyst 24 in each reactor 10.

6. Sampling and Analyzing

Array 120 is used to evaluate catalysts by determining their activityand selectivity. To accomplish this, at least a portion of each of theproduct mixtures flowing through each product conduit 40 is sampled andanalyzed to determine its composition. Preferably, analyzer 112 uses anyone of the following analytic techniques to determine each product gasescomposition; spectroscopy, spectrometry, chromatography, nuclearmagnetic resonance, or a combination thereof.

7. Reaction Heater

As with individual reactor 10, array 120 includes reaction heater 108shown in FIG. 6. Reaction heater 108 of array 120 provides heat forreaction zones 26 so that catalysts 24 can be kept at a controlledconstant temperature. Reaction heater 108 can be any type of heater toprovide the heat needed for reaction zones 26, such as analuminum-bronze oven using electrical resistance heating.

Although FIG. 6 shows a single reaction heater 108 common to allreactors 10 in array 120, in some cases it may be desirable that eachreactor 10 in array 120 have its own corresponding reaction heater 108so that different reactors 10 in array 120 may be kept at differenttemperatures. Similarly, it may be desirable in some cases to have twoor more reaction heaters 108, each reaction heater 108 providing energyfor one or more reactors 10 in array 120 so that there are blocks ofreactors 10 operating at different reaction temperatures.

D. Process of Evaporating and Reacting in an Array of Reactors

The process of vaporizing liquid feed and reacting the resulting vaporin the presence of catalyst 24 within each reactor 10 of array 120 issimilar to the process for an individual reactor 10. The processincludes the steps of introducing liquid feed to a plurality of reactors10, heating the liquid feed within each reactor 10, vaporizing theheated liquid feed within each reactor 10 to form a vapor andcontacting, at predetermined reaction conditions, the vapor withcatalyst 24 in each reactor 10 to form a product.

The liquid feed is introduced to each evaporation zone 18 in array 120simultaneously through injectors 48 so that reactors 10 of array 120 areoperating in parallel. The liquid feed in each reactor 10 is contactedwith packing 76 and then heated within each reactor 10 until it isvaporized within evaporation zones 18. Evaporator heater 20 provides theheat for each reactor 10 in array 120 so that the liquid feed in eachbed 78 reaches its bubble point very soon after it is injected into bed78.

The vapor in each reactor 10 then passes into receptacle 22 of eachreactor 10 through fluid permeable member 80. As with individual reactor10, a gas feed may be introduced in some cases and contacted withcatalyst 24 and vapor to react and form a product gas.

After passing through fluid permeable member 80 and into reaction zone26 of each reactor 10, the vapor and the gas feed, if present, areheated to a predetermined temperature by reaction heater 108. A singlereaction heater 108 may be used to provide the heat necessary tomaintain a predetermined temperature within each of the reaction zones26, or multiple reaction heaters 108 may be used to heat individualreaction zones 26, or blocks of reaction zones 26.

The temperature of catalyst 24 in each reaction zone 26 is constantlymeasured with a thermocouple 54. This temperature is then used tocontrol the setting of reaction heater 108 of array 120, or of theindividual corresponding heater for that particular reaction zone 26, orblock of reaction zones 26 as described above.

After being heated to a predetermined temperature, the vapor, the gasfeed and catalyst 24 are contacted in each reaction zone 26 of eachreactor 10 in array 120 so that they react and form a product mixture ofa product gas, byproducts and unreacted feeds. The product mixture thenexits from each of the reactors 10 through a corresponding productconduit 40. As with a single reactor 10, each of the product mixturesmay be diluted with a diluent gas that is mixed with the productmixtures in a corresponding mixing zone 110 after the product has beenformed in each of the reaction zones 26.

It is preferred that the chemical composition of the liquid feed, thegas feed and the diluent gas be known and that the liquid feed, the gasfeed and the diluent gas be introduced to each reactor 10 of array 120in measured.

At least a portion of each of the product mixtures is sampled andanalyzed by a corresponding analyzer 112 to determine its chemicalcomposition so that the activity, feed conversion, major product andbyproduct selectivities and yields for each catalyst 24 may becalculated.

Several advantages of the present invention are readily apparent. Theevaporation zone is versatile because it allows liquid phase feeds to befed as a gaseous fluid to a variety of different types of treatmentzones. Feeds of different phases may be mixed and fed as a gaseousmixture to the treatment zone. For example, a liquid phase feed may bevaporized and combined with a gas phase feed to form a continuous supplyof a gaseous mixture. With both the evaporation zone and the treatmentzone being in the same process vessel any need to transport the gaseousfeed through heat-traced conduits has been eliminated thereby minimizingthe possibility of feed components condensing out of the gaseous mixtureprior to encountering the treatment zone. In particular, the inventiveevaporation zone can be located within a process vessel that can beeasily and quickly assembled and disassembled using seals. Thevaporization of the liquid feed is accomplished without compromising theseals that allow the process vessel to be easily assembled.

The present invention should not be limited to the above-describedembodiments, but should be limited solely by the following claims.

1. A process vessel for evaporating a liquid feed and treating the resulting vapor comprising: an evaporation zone; a treatment zone; an insert containing at least one evaporation surface for evaporating feed and generating vapor, said insert positioned within the process vessel so that the evaporation surface is within the evaporation zone; a solids receptacle containing solid particles for treating the vapor, said solids receptacle positioned within the process vessel so that the solid particles are within the treatment zone; a housing having an inlet and an outlet and having the solids receptacle nested within the housing and the insert nested within the solids receptacle; and at least one heater associated with at least a portion of the process vessel.
 2. A process vessel according to claim 1, wherein the evaporation surface is selected from the group consisting of a bed containing packing, a porous monolith, a plate, a cone, and combinations thereof.
 3. A process vessel according to claim 1, wherein the insert is removable.
 4. A process vessel according to claim 1, wherein the solids receptacle is removable.
 5. A process vessel according to claim 1, further comprising a fluid permeable member attached to the receptacle to retain the solids but allow fluid to pass.
 6. A process vessel according to claim 1, further comprising a fluid permeable member attached to the insert to retain the evaporation surface but allow fluid to pass.
 7. A process vessel according to claim 1, further comprising an injector having an orifice, wherein said orifice is in the evaporation zone and the injector orifice and the evaporation surface are positioned relative to each other so as to prevent the formation of a drop at the orifice.
 8. A process vessel according to claim 1, further comprising an analyzer in fluid communication with the outlet of the housing.
 9. A process vessel according to claim 1, wherein the heater is associated primarily with the evaporation zone and further comprising a second heater associated primarily with the treatment zone.
 10. A process vessel according to claim 1, wherein said housing and said solids receptacle define a diluent inlet.
 11. An array of process vessels for evaporating a liquid feed and treating the resulting vapor in combinatorial processes comprising a plurality of process vessels and a heater associated with a portion of the process vessels, each process vessel having: an evaporation zone; a treatment zone; an insert containing at least one evaporation surface, the insert being positioned within the process vessel so that the evaporation surface is within the evaporation zone; a solids receptacle containing solid particles for treating vapor, the solids receptacle being positioned within the process vessel so that the solid particles are within the treatment zone; and a housing having at least one inlet and at least one outlet and having the solids receptacle nested within the housing and the insert nested within the solids receptacle.
 12. An array according to claim 10, wherein the inserts are removable.
 13. An array according to claim 10, wherein the receptacles are removable.
 14. An array according to claim 10, wherein the evaporation surfaces are selected from the group consisting of a bed containing packing, a porous monolith, a plate, a cone, and combinations thereof.
 15. An array according to claim 10, wherein the housings and the solids receptacles define diluent inlets. 